1. Field of the Invention
This invention relates to diphenyl oxide. In one aspect, this invention relates to a process of preparing diphenyl oxide from caustically hydrolyzing chlorobenzene. In another aspect, this invention relates to said caustic hydrolysis wherein phenol is a by-product.
2. Description of the Prior Art
Caustic hydrolysis of chlorobenzene is a process long known in the art for producing phenol and diphenyl oxide. Historically, phenol was the desired product and various methods of maximizing phenol yields were reported, such as recycling diphenyl oxide or adjusting the mole ratio of chlorobenzene to caustic. However, a number of different processes are available today for producing phenol, some economically more attractive than the caustic hydrolysis of chlorobenzene. Moreover, diphenyl oxide and other products from said caustic hydrolysis, such as phenylphenols and biphenylylphenyl ethers, have found commercial value. Consequently, phenol is no longer a necessarily desirable caustic hydrolysis product from chlorobenzene.
Where diphenyl oxide is the principally desired product, it is, of course, desirable to maximize its yield while minimizing the yield of phenol, preferably to a level where no net phenol (defined hereinafter) is produced. Heretofore reported caustic hydrolysis processes do not achieve this preferred objective.